Continuous rod making machines such as cigarette machines

ABSTRACT

A VARIABLE DIAMETER PULLEY FOR USE IN DRIVING THE GARNITURE TAPE OF A CONTINUOUS ROD CIGARETTE-MAKING OR FILTER PLUG-MAKING MACHINE COMPRISES A PLURALITY OF EQUALLY-SPACED RADIALLY SLIDABLE SEGMENTS EACH HAVING AN AXIAL PROTRUSION ENGAGING IN A CORRESPONDING CAM SLOT IN A CAM DISC. THE CAM DISC IS ROTATABLE RELATIVE TO THE SEGMENTS TO CAUSE RADIAL MOVEMENT OF THE SEGMENTS AND HENCE ALTER THE DIAMETER OF THE PULLEY. THE CAM SLOTS ARE ARRANGED IN TWO CONCENTRIC RINGS, OF DIFFERENT MEANS RADII, WITH THE CAM SLOTS IN THE TWO RINGS OVERLAPPING EACH OTHER, THAT IS TO SAY, EACH CAM SLOT SUBTENDS AN ANGEL AT THE CENTRE OF THE PULLEY GREATER THAN THE ANGULAR SPACING OF THE SEGMENTS.

P. A. MAW

Nov. 16, 1971 CONTINUOUS ROD MAKING MACHINES SUCH AS CIGARETTE MACHINES 2 Sheets-Sheet 1 Filed June 18, 1970 gwsm Nov. 16, 1971 P. A. MAW 3,620,092

CONTINUOUS ROD MAKING MACHINES SUCH AS CIGARETTE MACHINES Filed June 18, 1970 2 Sheets-Sheet Z United States Patent 3,620,092 CONTINUOUS ROD MAKING MACHINES SUCH AS CIGARETTE MACHINES Philip A. Maw, London, England, assignor to Molins Machine Company Limited, London, England Filed June 18, 1970, Ser. No. 47,317 Claims priority, application Great Britain, June 24, 1969, 31,794/ 69 Int. Cl. F16h 55/54 US. Cl. 74-23023 Claims ABSTRACT OF THE DISCLOSURE A variable diameter pulley for use in driving the garniture tape of a continuous rod cigarette-making or filter plug-making machine comprises a plurality of equally-spaced radially slidable segments each having an axial protrusion engaging in a corresponding cam slot in a cam disc. The cam disc is rotatable relative to the segments to cause radial movement of the segments and hence alter the diameter of the pulley. The cam slots are arranged in two concentric rings, of different mean radii, with the cam slots in the two rings overlapping each other; that is to say, each cam slot subtends an angle at the centre of the pulley greater than the angular spacing of the segments.

This invention is concerned with variable diameter pulleys, particularly for use in driving the garniture tape of a cigarette making machine or filter rod making machine. The garniture tape in a cigarette or filter rod making machine carries and moves the paper web which forms the wrapping around the tobacco or filter material filler. The speed of the garniture tape needs to be accurately controllable so that the speed of the continuous rod formed by the machine can be closely related tothe speed, for example, of the cut-off device which severe the continuous rod into short rods of an accurately controlled length. The speed of the garniture tape can be controlled by varying the diameter of the pulley driving the tape.

A pulley according to the present invention comprises a plurality of slidable segments which engage the tape and are constrained to move radially, and a cam disc rotatable relative to the segments, the cam disc having in it at least two sets of similar cam slots forming concentric rings at different mean radii, of which each slot subtends an angle at the axis of the pulley greater than the angular spacing of the segments, successive segments having axial protrusions engaging in slots in the different sets so that rotation of the cam disc relative to the segments causes the segments to move radially, thereby altering the diameter of the pulley.

Preferably the cam disc has two sets of slots and alternate segments have axial protrusions engaging in slots in the different sets.

In a preferred arrangement the segments are constrained to move radially by means of a second disc. The segments may be held firmly in position during use by clamping the two discs together.

Conveniently the pulley also incorporates a clutch enabling the pulley to be disengaged from its shaft for free rotation.

An example of a garniture tape pulley according to this invention is shown in the accompanying drawings. In these drawings:

FIG. 1 is a cross-section of the pulley taken approximately on a line II in FIG. 4;

FIG. 2 is a fragmentary section on the line 11-11 in FIG. 1;

FIG. 3 is a section on the line III-III in FIG. 1; and

FIG. 4 is an end view of the scroll showing the pins engaging in the cam slots.

As shown in FIG. 1, the pulley is mounted on a drive shaft 10' which extends from a stationary casing 12, being supported by a number of bearings including a roller bearing 14. The pulley includes a main annular body 16 which is rotatable on the shaft 10 and is driven indirectly from the shaft in a manner such that the drive can be disengaged, as will be described further on.

The periphery of the pulley is formed by eight segments 18 which are evenly spaced around the axis of the pulley. Each segment 18 includes a radially extending portion 20 which has parallel sides lying parallel to a centre line of the segment which passes through the axis of the pulley. Wedge-shaped parts 22 on the body 16 of the pulley guide the segments by co-operation with the parallel sides of the portions 20 of the segments. This allows the segment to be moved radially in order to adjust the diameter of the pulley.

Radial adjustment of the positions of the segments 18 is achieved by means of a cam disc 24 which is formed with cam slots 26 (shown particularly in FIG. 4) which are regularly spaced around the axis of the disc, though at alternating mean radii. It will be seen that the two sets of slots form rings at different mean radii. Each segment 18 has secured to it a pin 28, for example about 10 mm. diameter, which engages in one of the cam slots 26, alternate pins corresponding to different radii, as shown in FIG. 4. The slots all extend over a considerable are (which in the example shown is so as to allow for fine adjustment of the pulley diameter by virtue of the fact that the inclination at any particular point to a tangent to a circle passing through that point is relatively small. In other words, rotation of the disc 24 relative to the body 16 of the pulley produces a slow rate of radial movement of the segments 18. In the illustrated example, the total angular movement of the disc (which corresponds to the arc covered by each slot 26), is 80 and the total radial movement of the segments 18 from one extreme to the other is 3 millimetres. The nominal diameter of the pulley is 2.70 mm. The circumferential overlap of the slots, as shown in FIG. 4, accounts for the fact that the sectional view of FIG. 1 shows two slots 26 on each side of the pulley axis.

Rotation of the cam disc to adjust the pulley diameter is achieved by rotating a pinion 30 which is mounted on a shaft 32 and meshes with an internal gear 34 in the disc 24. The shaft 32 has a square-sectioned end portion 36 by which it can be rotated with the aid of a spanner.

When the cam disc has been rotated to a desired position it is locked by tightening a number of bolts 38 which act on an annular clamping member 40 which clamps the cam disc against the body 16 of the pulley.

The shaft 10 drives the pulley via a coupling in the form of a collar 41 which is normally locked in by a clutch sleeve 42. The collar 41 is splined to the shaft so that it rotates with the shaft but can move axially with respect to the shaft. Axial movement is necessary in order to disengage the drive between the collar 41 and the body 16 of the Wheel, this drive being via intermeshing gear teeth 43 respectively on the collar and on a member 44 which is secured to the body 16 of the pulley by bolts 46'. The drive is discontinued when the collar 41 is moved axially away from the member 44 so as to disengage the driving gear teeth 43.

During use the coupling collar is held axially in the position shown in FIG. 1 by two detent pieces in a radial the plunger 50 (which is rounded) seats in a shallow recess 54 in the clutch sleeve 42. The clutch sleeve can however be rotated in an anti-clockwise direction (as viewed in FIG. 3) to a position in which the plunger 50 enters a deeper recess 56 in the clutch sleeve; the ball 48 can then move out of the recess in the shaft, against spring pressure, so as to permit the collar 41 to be moved axially by pulling the clutch sleeve 42. The collar 41 moves axially with the clutch sleeve because of three studs 58 which are screwed into the collar and have heads engaging in circumferential slots 60 in the clutch sleeve. These studs also serve to retain the clutch sleeve in position on the collar. The slots 60 permit the necessary relative angular movement between the clutch sleeve and the collar.

As has already been mentioned, FIG. 3 shows the clutch sleeve in a position in which it permits the collar to be withdrawn, from engagement with the member 44. In order to secure the collar 41 in its driving position, after it has been moved into engagement with the member 44, the clutch sleeve is rotated in a clockwise direction with respect to the collar 41 until the studs 58 reach the opposite ends of the slots 60, whereupon the plunger 50 again seats in the relatively shallow recess 54 and holds the ball 48 in the recess in the shaft so as to prevent axial movement of the collar and clutch sleeve.

When the drive between the shaft 10 and the pulley is disengaged for test purposes or for any other reason, the pulley can be rotated manually via a wheel 62 secured to the clamping member 40.

I claim:

1. A variable diameter pulley comprising a plurality of slidable segments constrained to move radially, and a cam disc rotatable relative to the segments, the cam disc having in it at least two sets of similar cam slots forming concentric rings at different mean radii, at which each slot subtends an angle at the axis of the pulley greater than the angular spacing of the segments, successive segments having axial protrusions engaging in slots in the different sets so that rotation of the cam disc relative to the segment causes the segments to move radially thereby altering the diameter of the pulley.

2. A pulley according to claim 1 in which the cam disc has two sets of slots and alternate segments have axial protrusions engaging in slots in the different sets.

3. A pulley according to claim 1 including a second disc formed with a radial parallel-sided channel for each segment which cooperates with a parallel-sided part of the segment to constrain the segment to move radially.

4. A pulley according to claim 3 in which the segments can be held firmly in position by clamping the two discs together.

5. A pulley according to claim 4 in which the discs are clamped together by means of a number of circumferentially spaced bolts which screw into the second disc and transmit a clamping force to the cam disc via an annular clamping member.

6. A pulley according to claim 1 in which the angular position of the cam disc is adjustable by means of a shaft carrying a gear which meshes with gear teeth formed on the cam disc.

7. A variable diameter pulley for driving the garniture tape of a continuous rod making machine, for making cigarettes, filter plugs or like articles, the pulley comprising a plurality of radially movable segments adjustable by means of a rotary cum to vary the pulley diameter, and including a clutch comprising coaxial driving and driven members, a coupling which is axially movable between an engaged position in which it links the driving and driven members and a disengaged position in which the two members are not linked, and a control member which is movable relative to the coupling between a first position and a second position, the coupling having a radial bore containing two detent pieces urged apart by a spring, one detent piece being arranged to engage normally in a recess in the driving or driven member, and the second detent being engageable in spaced recesses in the control member when the control member is respectively in its two positions, the recess engaged by the second detent when the control member as in its first position being relatively shallow so that the first detent is held firmly in the recess in the driving or driven member, whereas the recess engaged by the second detent when the control member is in its second position is deeper so that the first detent can ride easily out of the recess in the driving or driven member when the control member is moved axially to disengage the coupling.

8. A pulley according to claim 7 in which the control member is held against axial movement relative to the coupling but can rotate relative to the coupling, the recesses in the control member being circumferentially spaced in it so that by rotation of the control member relative to the coupling either of the recesses can be engaged by the second detent.

9. A pulley according to claim 7 in which, when the control member is in its first position, the two detents abut so as positively to prevent the first detent from riding out of its corresponding recess, thus positively locking the coupling in position.

10. A variable diameter pulley for driving the garniture tape of a continuous rod making machine, for making cigarettes, filter plugs or like articles, comprising two spaced coaxial discs; a plurality of circumferentially spaced segments lying between the discs, means on one of the discs for constraining the segments so that they can move only radially; cam means on the second of the discs for controlling radial positions of the segments, the said second disc being rotatable relative to the first disc, the said cam means comprising two sets of similar cam slots forming two concentric rings at different mean radii, there being one cam slot for each segment, each slot subtending at the axis of the pulley an angle greater than the angular spacing of the segments; protrusion means on each segment arranged to engage in a corresponding one of the cam slots, alternate segments having their protrusions engaging in slots in the different sets; and including a plurality of circumferentially spaced bolts engaging the first disc and a clamping ring abutting against the second disc, whereby tightening of the bolts acts to clamp the segments between the two discs.

References (Iited UNITED STATES PATENTS 652,092 6/1900 Desprez et al 74230.23 742,497 l0/l903 Rowand 74230.23 758,474 4/1904 Reed 74-23023 896,160 8/1908 Rosewarne 74-23023 2,628,706 2/1953 Guba 74-230.Z3

CORNELIUS J. HUSAR, Primary Examiner 

